Experimental adenomas and carcinomas of the large intestine behave as distinct entities: Most carcinomas arise de novo in flat mucosa
Experimental adenomas and carcinomas of the large intestine behave as distinct entities: Most carcinomas arise de novo in flat mucosa
复制标题
实验性大肠腺瘤和癌表现为不同的实体：大多数癌是在扁平粘膜中从头产生的
作者：
A. Maskens;R. Dujardin
对 152 只二甲肼 (DMH) 治疗的大鼠的大肠肿瘤进行了详细的组织学分析。总共 539 例腺肿瘤中，45 例为良性； 494 例（92%）为局部侵入性；其中 222 个（41%）侵犯固有肌层。 141 个肿瘤直径≥3mm。其中，127 例（90%）是侵入性的。除了肉眼可见的结节外，在扁平粘膜的连续切片上还观察到了几种显微镜下的癌。良性息肉通常比癌的潜伏期更长。文献综述表明，在大多数大鼠实验中，大多数或所有 DMH 诱导的肿瘤都是侵袭性癌，通常不存在腺瘤。经常报道显微镜下浸润性癌。所有这些数据构成了强有力的证据，表明大多数实验性腺癌确实是在平坦粘膜中从头产生的，即没有先前的腺瘤阶段。然而，据报道，大多数 DMH 诱导的小鼠肿瘤是腺瘤，要么单独存在，要么与癌共存。有人认为，“新发癌”和腺瘤性息肉虽然都是由相同的致癌物诱发，并且可以在某些实验系统中共存，但它们构成了独立且不同的病理实体；它们可以通过遗传易感性来区分。
Detailed histologic analyses were performed on tumors of the large intestine obtained in 152 dimethylhydrazine(DMH)‐treated rats. Of a total 539 glandular neoplasms, 45 were benign; 494 (92%) were locally invasive; of which 222 (41%) were invading the muscularis propria. One‐hundred‐forty‐one tumors were ≧3mm in diameter. Among those, 127 (90%) were invasive. In addition to macroscopic nodules, several microscopic carcinomas were observed on serial sections of flat mucosa. The benign polyps usually appeared after longer latency periods than did carcinomas. A review of the literature indicates that in the majority of rat experiments most or all DMH‐induced tumors were invasive carcinomas, often in the absence of adenomas. Microscopic invasive carcinomas were frequently reported. All these data constitute strong evidence that most experimental adenocarcinomas do arise de novo in flat mucosa, i.e., without a prior adenoma stage. However, most DMH‐induced tumors in mice were reported to be adenomas, either alone or coexisting with carcinomas. It is suggested that “de novo arising carcinomas” and adenomatous polyps, which are both inducible by the same carcinogens, and which can coexist in some experimental systems, nonetheless constitute independent and distinct pathologic entities; they can be separated by genetic susceptibility.